How to apply interfacing

My head has been fuzzy for the past two days. Yesterday it was Wednesday and today, it’s been the 5th of May for two days running. Do you ever have weeks like that?

A woman came to take a class with me 12 years ago. The week prior to her arrival, she’d spent four and a half days with a “couture” sewing celeb who taught her to apply interfacing by holding the iron in place for a count of ten. This I discovered when I put “M” to applying interfacing to leather and contrary to my instruction (she was eager to apply the proceeds of that $3,000 fee) she insisted on the ten second count and of course, the piece was shriveled and burnt beyond recognition. It looked like a pig’s ear that had gotten too much sun. I saved that piece for a long time, I don’t know where it went now. Lately I’ve been reading that people still do this. The horror of it all. I thought it was an isolated incident but it would seem it is not. The very idea makes me shudder all over.

If you consult industry interfacing experts -the people who make fusing machines-, they’ll tell you that applying fusibles relies on three things, time, pressure and heat. I’d add a fourth and fifth element, that of having the right fusible for the right fabric in the first place and the right tools. Of the three five, time is but one facet and not really the major one. Not when a fusing machine can fuse fabrics at 26 feet a minute. Even then, time is better calculated as during and after. It can take but a second to apply interfacing but it can take a few seconds for it to cool enough to move it.

The right product:
I don’t think enough weight is given to selecting the right interfacing. I get the idea that many think fusible is like sugar in a recipe, any brand for any use will do. It should be just as variable as your fabric. It is more typical than not to buy interfacing specifically for a given fabric. It is also common to have two or more kinds used in the same product depending on the desired performance. Even the amount of glue and pattern of its application matters. If I have to pick from the selection at the fabric store, I tend to select based on the backing (glue dispersal) rather than the weight. For example, if you want to interface a nubby boiled wool, you want an interfacing that withstands the high pressing temperatures wool requires (in subsequent pressing operations) and that has a lot of fat glue drops on the underside. If an interfacing doesn’t stick, it doesn’t necessarily mean the fusible, nor the fabric it is applied to, is cheap. It only means the two mediums are not complimentary for optimal adhesion.

Larger firms have established relationships with vendors. The manufacturer sends a fabric swatch to the supplier and the supplier tests applications of various interfacing products to make a recommendation. The sample is returned to the customer for a final decision. As small companies, you don’t have such amenities. You’ll have to hunt and peck between available options and test pressing samples. Be sure to wash test them for stability. And no, I can’t be more specific than that. If all of you would be so kind as to make an identical product of identical materials for an identical application, then I would. But no, all of you stubbornly persist in producing a gamut of products that defy neat solutions so it is your fault.

The right temperature:
If you have to hold an iron in place for ten seconds to meld the goods, there is a mismatch between the fabric and fusible OR your iron isn’t hot enough. The right temperature for the right fabric for the right fusible is the temperature rating of the fabric itself. The fabric governs the heat relationship.

The right tools:
Worry less about arcane solutions that don’t solve but a few problems and get things that will solve most of them. Case in point, get a silicone foot for your iron. No, there are no worthwhile substitutes so if you can’t get one for your iron and you’re serious about it, you probably need another iron (see related entries for suggestions). With a silicone foot, you will only rarely (if ever) need a pressing cloth and if you do, you’re more likely to need it under the goods you’re pressing, not above it. This also presumes (of course) that you’ve cut the fusible to be smaller than the area to which it is being applied. Sure, that takes longer in the front end but less time in pressing. You also don’t have to worry about cleaning up a mess on your board. Another example is fusing interfacing to velvets (yes, I do it all the time). When fusing velvet, put a scrap of velvet under the work piece with naps facing each other.

The right pressure:
I think people also use time as a substitute for pressure. There’s two kinds of pressure. One is weight and the other is PSI -steam. You don’t necessarily need a heavy iron but don’t buy something that feels like a toy. You should never have to apply pressure (weight) with the iron. In a perfect world, you could afford an iron for which the amount and temperature of steam is independent of the iron plate temperature (a boiler iron). If not, a gravity feed may be a solution. If the fabric is low temp and rated below what will generate steam from the iron, a quick spritz with a water bottle should be all you need. That sort of pressing may take a second or two longer but only because the low iron heat needs more time to evaporate the water.

The right time:
If all the governing factors are balanced, fusing interfacing should not take any longer or be any different than normal pressing. If your fusing is taking too long, time is the symptom of a more complex problem rather than its solution.

Related:
Interfacing: 10 tips
How to select commercial pressing equipment
How to select commercial pressing equipment pt.2
SPESA Trip Report: Kathleen pt.2

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